Reinforcing steel of classes A500 and A600 comprises a hot-rolled rod having the cross section being close to a circle and inclined ribbed protrusions on its surface (see GOST K 52544-2006. Weld reinforcing rolled stock of periodical profile, Classes A500C and B500C, for reinforcing ferroconcrete structures. Engineering Specification).
The disadvantage of the known reinforcing steel is a low technological effectiveness in the manufacture of monolithic structures due to its production in the form of sections of standard length, which makes it necessary to get each reinforcing element by connecting a plurality of sections butt-to-butt by welding, which leads to weakening of each section in the weld points. Another disadvantage of the traditional reinforcing steel is its low corrosion resistance of a reinforcing structure made of it due to centers of corrosion in the place of welding, as well as the practical impossibility of using zinc anticorrosive coating because of the extremely low weldability in the case of such coating deposition. The closest analogue to the claimed article is a reinforcement cable comprising a central wire and wires winding in a spiral around said central wire with a periodic profile in the form of protrusions and depressions. At the same time the periodic profile is applied throughout the whole surface of the wound wires (see DE 1659265).
Said cable can be made in the form of a single product of an arbitrary length, and it can self-strengthen and has a mechanical engagement in the direction of screwdriving. However it does not provide the strong adhesion to concrete because of the narrow gaps between the circumference around the cross-section of the cable and the surface of the outer wires. There is no space remaining for the formation of strong ridges of concrete under the generating line of the cable. What is more, the disadvantage of the cable is in that the physical and mechanical properties do not correspond to the requirements of the embedded reinforcement due to the fact that the strength provided by the high strength of the wire is not realized in the cross-sectional dimensions which are greatly inferior to the transverse dimensions of the cross section of hot-rolled reinforcing steel of equal aggregate strength due to the relatively small contour of enveloping.
A method of reinforcing ferroconcrete structures is disclosed in prior art. Said method comprises mounting nontensioned reinforcement in the direction of the largest extension of the structures and in the transverse directions, cyclic constructing of a casing, and filling the space inside the casing with concrete, while hot-rolled rods of standard length are used as reinforcement rods connected butt-to-butt by welding or through threaded bushing after completing the cycle of the construction of the ferroconcrete element (see Code of Regulations SP 52-103-2007 “Monolithic Ferroconcrete Constructions”).
The disadvantages of this method of reinforcement are low strength of the reinforcing elements, in particular low specific strength and high creeping of reinforcing rods because of the many places of connection of each reinforcement rod in length, so that a rod cannot not take the load as a single structure, and the high cost of reinforcement due to the low specific strength of reinforcing rods and high labor expenditures because of the numerous repetitive butting of the reinforcing elements.
The closest analog to the claimed method of manufacturing is a method of manufacturing reinforcement cables comprising producing wires of round cross section, forming a periodic profile on the outer wires, cabling the wires, and subsequent compressing. The periodic profile is applied to the entire surface of the wires before cabling, and after cabling the elastic compression is carried out by drawing the cable through a crimping die (see German patent DE 1659265, E 04 C 5/03).
The disadvantage of this method is it is impossible to produce a reinforcement cable with physical and mechanical properties required for insertion reinforcement due to the fact that the manufactured cable has a cross section close to a circle, which does not allow realizing its strength characteristics due to insufficient contour of enveloping. In addition, the adhesion of the cable to concrete is lower than that of a hot-rolled profiled reinforcement.
The technical problem solved by the invention is to create a self-straightening reinforcing element with an arbitrarily large length with strength characteristics and the enveloping contour of the section at the level of hot-rolled reinforcing steel of grades A500 and A600, adhesion to concrete and other characteristics not below the level of hot-rolled reinforcing steel of grades A500 and A600, as well as improved corrosion resistance due to unlimited possibility of applying anticorrosion coatings.
The problem is solved in the following way. In the prior art a reinforcement cable comprises a central wire and wires spiraling around the central wire with a periodic profile.